[FEAT] Added valyu integration (#359)

* [FEAT] Added valyu integration

* Apply suggestion from @bilgeyucel

* Apply suggestion from @bilgeyucel

* Apply suggestion from @bilgeyucel

---------

Co-authored-by: Bilge Yücel <bilge.yucel@deepset.ai>

Author: alexngys

integrations/valyu.md

@@ -0,0 +1,290 @@
+---
+layout: integration
+name: Valyu Search
+description: Search and content extraction components using Valyu's API for web and proprietary sources
+authors:
+  - name: Valyu
+    socials:
+      github: valyu-network
+pypi: https://pypi.org/project/valyu-search-haystack
+repo: https://github.com/valyu-network/valyu-search-haystack
+type: Search & Extraction
+report_issue: https://github.com/valyu-network/valyu-search-haystack/issues
+version: Haystack 2.0
+toc: true
+---
+
+### Table of Contents
+
+- [Overview](#overview)
+- [Installation](#installation)
+- [Usage](#usage)
+  - [ValyuSearch](#valyusearch)
+  - [ValyuContentFetcher](#valyucontentfetcher)
+  - [Pipeline Examples](#pipeline-examples)
+  - [Advanced Configuration](#advanced-configuration)
+- [API Integration Details](#api-integration-details)
+  - [Authentication](#authentication)
+  - [License](#license)
+
+## Overview
+
+[![PyPI - Version](https://img.shields.io/pypi/v/valyu-search-haystack.svg)](https://pypi.org/project/valyu-search-haystack)
+[![PyPI - Python Version](https://img.shields.io/pypi/pyversions/valyu-search-haystack.svg)](https://pypi.org/project/valyu-search-haystack)
+
+Haystack components for integrating [Valyu](https://docs.valyu.ai/overview)'s powerful search and content extraction APIs into your Haystack pipelines.
+
+This package provides two main components:
+
+- **`ValyuSearch`** - Search component that queries the Valyu DeepSearch API and returns documents with content already included
+- **`ValyuContentFetcher`** - Content extraction component that fetches and cleans content from URLs
+
+**Key Features:**
+
+- Search across web and proprietary sources
+- Full content included in search results
+- AI-powered content extraction and summarization
+
+---
+
+## Installation
+
+Use `pip` to install Valyu Search for Haystack:
+
+```console
+pip install valyu-search-haystack
+```
+
+Or install from source:
+
+```console
+pip install -e .
+```
+
+**Requirements:**
+
+- Python 3.8+
+- haystack-ai >= 2.0.0
+- valyu >= 2.2.1
+
+## Usage
+
+Set your Valyu API key as an environment variable:
+
+```bash
+export VALYU_API_KEY="your-api-key"
+```
+
+### ValyuSearch
+
+The `ValyuSearch` component integrates with the Valyu DeepSearch API. Unlike many search APIs, Valyu returns full content by default, making it ideal for RAG pipelines.
+
+**Basic Usage:**
+
+```python
+from valyu_haystack import ValyuSearch
+from haystack import Pipeline
+
+# Create a search component (API key from VALYU_API_KEY env var)
+search = ValyuSearch(
+    top_k=5,
+    search_type="all",  # "web", "proprietary", or "all"
+    relevance_threshold=0.5
+)
+
+# Create and run a pipeline
+pipeline = Pipeline()
+pipeline.add_component("search", search)
+
+result = pipeline.run({"search": {"query": "What is Haystack AI?"}})
+documents = result["search"]["documents"]
+links = result["search"]["links"]
+```
+
+**Component Parameters:**
+
+- `api_key` (Secret): Your Valyu API key. Defaults to `VALYU_API_KEY` environment variable
+- `top_k` (int, default=10): Maximum number of results to return
+- `api_base_url` (str): Base URL for the Valyu API
+- `search_type` (Literal["web", "proprietary", "all"], default="all"): Type of search
+- `relevance_threshold` (float, default=0.5): Minimum relevance score (0.0-1.0)
+- `max_price` (int, default=100): Maximum price per thousand queries in cents
+
+**Output:**
+
+- `documents` (List[Document]): Documents with content and rich metadata
+- `links` (List[str]): List of URLs from search results
+
+**Metadata included:**
+
+- `title`: Page title
+- `url`: Source URL
+- `description`: Page description
+- `source`: Data source identifier
+- `relevance_score`: Relevance score (0.0-1.0)
+- `price`: Cost of this result
+- `length`: Content length in characters
+- `data_type`: Type of data ("structured" or "unstructured")
+- `image_url`: Associated image URL (if any)
+
+### ValyuContentFetcher
+
+The `ValyuContentFetcher` component extracts clean, readable content from URLs using the Valyu Contents API. It supports batch processing and AI-powered summarization.
+
+**Basic Usage:**
+
+```python
+from valyu_haystack import ValyuContentFetcher
+from haystack import Pipeline
+
+# Create a content fetcher component
+fetcher = ValyuContentFetcher(
+    extract_effort="normal",  # "normal", "high", or "auto"
+    response_length="short",  # "short", "medium", "large", "max", or int
+    summary=True  # Enable AI summarization
+)
+
+# Create and run a pipeline
+pipeline = Pipeline()
+pipeline.add_component("fetcher", fetcher)
+
+urls = ["https://example.com/article1", "https://example.com/article2"]
+result = pipeline.run({"fetcher": {"urls": urls}})
+documents = result["fetcher"]["documents"]
+```
+
+**Component Parameters:**
+
+- `api_key` (Secret): Your Valyu API key. Defaults to `VALYU_API_KEY` environment variable
+- `api_base_url` (str): Base URL for the Valyu API
+- `timeout` (int, default=30): Request timeout in seconds
+- `extract_effort` (Literal["normal", "high", "auto"], optional): Extraction thoroughness
+- `response_length` (Union[Literal["short", "medium", "large", "max"], int], optional): Content length per URL
+- `summary` (Union[bool, str, Dict], optional): AI summary config
+  - `False` or `None`: No AI processing (raw content)
+  - `True`: Basic automatic summarization
+  - `str`: Custom instructions (max 500 chars)
+  - `dict`: JSON schema for structured extraction
+
+**Input:**
+
+- `urls` (List[str], optional): List of URLs to fetch
+- `documents` (List[Document], optional): Documents with URLs in metadata
+
+**Output:**
+
+- `documents` (List[Document]): Documents with extracted content
+
+**Metadata included:**
+
+- `url`: Source URL
+- `title`: Page title
+- `length`: Content length in characters
+- `source`: Data source identifier
+- `data_type`: Type of content
+
+### Pipeline Examples
+
+**RAG Pipeline with Search and Chat:**
+
+```python
+from haystack import Pipeline
+from haystack.utils import Secret
+from haystack.components.builders.chat_prompt_builder import ChatPromptBuilder
+from haystack.components.generators.chat import OpenAIChatGenerator
+from haystack.dataclasses import ChatMessage
+from valyu_haystack import ValyuSearch
+
+# Create components
+web_search = ValyuSearch(top_k=3)
+
+prompt_template = [
+    ChatMessage.from_system("You are a helpful assistant."),
+    ChatMessage.from_user(
+        "Given the information below:\n"
+        "{% for document in documents %}{{ document.content }}{% endfor %}\n"
+        "Answer question: {{ query }}.\nAnswer:"
+    )
+]
+
+prompt_builder = ChatPromptBuilder(template=prompt_template, required_variables={"query", "documents"})
+llm = OpenAIChatGenerator(api_key=Secret.from_env_var("OPENAI_API_KEY"), model="gpt-4o-mini")
+
+# Build pipeline
+pipe = Pipeline()
+pipe.add_component("search", web_search)
+pipe.add_component("prompt_builder", prompt_builder)
+pipe.add_component("llm", llm)
+
+# Connect components
+pipe.connect("search.documents", "prompt_builder.documents")
+pipe.connect("prompt_builder.messages", "llm.messages")
+
+# Run pipeline
+query = "What is the most famous landmark in Berlin?"
+result = pipe.run(data={"search": {"query": query}, "prompt_builder": {"query": query}})
+```
+
+**Indexing Pipeline with Content Fetcher:**
+
+```python
+from haystack import Pipeline
+from haystack.document_stores.in_memory import InMemoryDocumentStore
+from haystack.components.writers import DocumentWriter
+from valyu_haystack import ValyuContentFetcher
+
+# Create components
+document_store = InMemoryDocumentStore()
+fetcher = ValyuContentFetcher()
+writer = DocumentWriter(document_store=document_store)
+
+# Build indexing pipeline
+indexing_pipeline = Pipeline()
+indexing_pipeline.add_component(instance=fetcher, name="fetcher")
+indexing_pipeline.add_component(instance=writer, name="writer")
+
+# Connect components
+indexing_pipeline.connect("fetcher.documents", "writer.documents")
+
+# Run pipeline
+indexing_pipeline.run(data={
+    "fetcher": {"urls": ["https://haystack.deepset.ai/blog/guide-to-using-zephyr-with-haystack2"]}
+})
+```
+
+### Advanced Configuration
+
+**Structured data extraction with Content Fetcher:**
+
+```python
+from valyu_haystack import ValyuContentFetcher
+
+# Define JSON schema for structured extraction
+schema = {
+    "type": "object",
+    "properties": {
+        "title": {"type": "string"},
+        "author": {"type": "string"},
+        "published_date": {"type": "string"},
+        "summary": {"type": "string"}
+    }
+}
+
+fetcher = ValyuContentFetcher(summary=schema)
+result = fetcher.run(urls=["https://example.com/article"])
+
+# Extracted structured data will be in document metadata
+```
+
+## API Integration Details
+
+### Authentication
+
+Both components use Haystack's `Secret` class for secure API key management:
+
+- Header: `x-api-key: your-api-key`
+- Environment variable: `VALYU_API_KEY`
+
+### License
+
+`valyu-search-haystack` is distributed under the terms of the [Apache-2.0](https://spdx.org/licenses/Apache-2.0.html) license.